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Biomedical subjects

H Okudaira

Publications and source records attributed to H Okudaira.

At least 55 records · Page 3Linked to original sources
PubMed1997

Engineering of the major house dust mite allergen Der f 2 for allergen-specific immunotherapy.

A major problem with allergen-specific immunotherapy involving repeated injection of allergens is the risk of an anaphylactic reaction. We engineered the major house dust mite allergen, Der f 2, to reduce its capacity to induce skin test reactivity and histamine release from peripheral blood basophils in allergic patients. The engineered allergen, in which the disulfide bond that linked the N- and C-terminal sequences of Der f 2 was disrupted, retained T-cell epitopes essential for immunotherapy and ability to stimulate T-cell proliferation. Such engineered allergens are potentially useful for safer and more effective immunotherapy for allergies.

Allergens↗
PubMed1997

Increased IL-6 and IL-8 in bronchoalveolar lavage fluids (BALF) from patients with sarcoidosis: correlation with the clinical parameters.

A variety of cytokines have been implicated in the pathogenesis of pulmonary sarcoidosis, but the exact roles of IL-6 and IL-8 are not yet clear. We studied these cytokine levels in BALF from patients with pulmonary sarcoidosis, idiopathic pulmonary fibrosis (IPF), systemic screlosis (SSc) with interstitial lung disease and control subjects. IL-6 and IL-8 levels were significantly elevated in sarcoidosis, IPF and SSc with interstitial lung disease compared with control subjects. Subjects with sarcoidosis had significantly increased levels of both cytokines compared with controls when the cytokine values were corrected by the total albumin content and the two cytokine levels correlated with each other (r = 0.876). BALF IL-6 levels correlated with percent lymphocytes and percent CD3+ cells. Moreover, when sarcoidosis patients were divided into three groups, those who needed steroid therapy or had progressive disease showed increased cytokine levels in BALF over stable or improved patients. These observations suggest that locally derived IL-6 and IL-8 were increased in sarcoidosis and correlated with activity of this granulomatous lung disease.

Adult↗
PubMed1997

Genomic organization and polymorphisms of the major house dust mite allergen Der f2.

We amplified genomic DNA encoding the major house dust mite allergen, Der f2, from Dermatophagoides farinae by means of the polymerase chain reaction and cloned it into Escherichia coli. The nucleotide sequences of the amplified fragments were determined and compared with those of the cDNA previously reported. Four Der f2 genomic clones were obtained, suggesting that the genomic Der f2 gene had sequence polymorphisms like the cDNA clones. Each of the genomic clones had a single small intron. With respect to the exon sequences, two of the four genomic clones were identical with two cDNA clones, respectively. The others were combinations of the two clones. Genomic Southern blotting suggested that the Der f2 gene is located at one locus in the mite genome and that sequence substitutions were due to polymorphisms among individual mite genes.

Allergens↗
PubMed1997

Development of lung eosinophilic inflammation by the infusion of IL-5-producing T cell clones.

To delineate the critical role of T cells on asthma, we tested whether eosinophilic inflammation of the bronchial mucosa is induced by transfer of IL-5-producing T cell clones, in the absence of antigen-specific immunoglobulins (IgE, A and G). Ovalbumin-specific T cell clone, FI5, that produced IL-5 upon challenge with relevant antigen was established. Eosinophilic inflammation of the lung occurred when unprimed mice were transferred with FI5 and challenged by the inhaled antigen. Eosinophil infiltration was completely suppressed by the administration of anti-IL-5 neutralizing antibody, indicating the essential role of IL-5. We concluded that the existence of IL-5-producing helper T cells is sufficient for the development of airway eosinophilic inflammation.

Animals↗
PubMed1997

Successful transfer of late phase eosinophil infiltration in the lung by infusion of helper T cell clones.

Bronchial asthma is characterized by chronic eosinophilic inflammation of the bronchial mucosa. Accumulating evidences suggest that activated T cells and T cell cytokines play critical roles in the local accumulation and activation of eosinophils. To further delineate the critical role of T cells on asthma, we tested the possibility whether eosinophilic inflammation of the bronchial mucosa is induced by transferred T cell clones, in the absence of antigen-specific immunoglobulins (IgE, A, and G). Ovalbumin-specific Th2 clones were established and cytokine profiles were determined. Eosinophilic inflammation accompanied with airway hyperresponsiveness occurred only when unprimed mice were transferred with IL-5 producing Th2 clones and challenged by the inhalation of relevant antigen. Increase of IL-5 concentration in bronchoalveolar lavage fluid (BALF) was detected after the challenge, indicating the local production of cytokines by the transferred T cells, and preceded the appearance of the airway eosinophilia. Eosinophil infiltration was completely suppressed by the administration of anti-IL-5 neutralizing antibody, indicating the essential role of IL-5 in this model. The intensity of the eosinophil accumulation in vivo correlated well with the capacity of the T cell clones to produce IL-5 in vitro. We concluded that the existence of IL-5-producing helper T cells is sufficient for the development of the eosinophilic inflammation at the bronchial mucosa upon inhalation challenge of the relevant antigen.

Animals↗
PubMed1997

Challenge studies of a leukotriene receptor antagonist.

The leukotriene receptor antagonist pranlukast (SB 205312, ONO-1078) has demonstrated clinical activity as an antiasthma drug in traditional challenge models, including exercise-induced asthma and inhaled bronchoprovocations with sulpyrine (an aspirin analogue), antigen, methacholine, leukotriene C4, and leukotriene D4. This article reviews the results of a published sulpyrine-challenge study and two unpublished house dust mite antigen challenge studies. Statistically significant attenuation of the decrease in FEV1 induced by bronchoprovocation was observed with pranlukast compared with placebo or baseline control in all challenge studies. These challenge studies demonstrate that pranlukast significantly protects against aspirin-induced bronchoconstriction and significantly attenuates both the immediate (early) and late airway responses to inhaled allergen.

Anti-Asthmatic Agents↗
PubMed1997

[Hypereosinophilia after allogeneic bone marrow transplantation. A possible role of IL-5 overproduction by donor T-cells chronic GVHD].

Chronic graft-versus-host disease (GVHD) is thought to result from abnormalities of several cytokine regulations in vivo. We analyzed interleukin-5 (IL-5) production by peripheral lymphocytes in a patient showing hypereosinophilia associated with chronic GVHD after allogeneic bone marrow transplantation. IL-5 production by activated T-lymphocytes which are known to play a major role in chronic GVHD was upregulated when stimulated by PMA + ionomycin. Therefore, hypereosinophilia observed in our patient may be correlated with IL-5 production in donor T-lymphocytes.

Adolescent↗
PubMed1997

Two differential effects of cyclic adenosine 3',5'-monophosphate on IL-5 production by antigen-specific human T cell line.

It has been proven that increasing cyclic adenosine 3',5'-monophosphate (cAMP) in human helper T cells results in decreased production of interleukin (IL)-2. As we have recently found that IL-2 stimulates IL-5 production, the effects of cAMP on IL-5 synthesis of T cells was investigated in this study. Prostaglandin E2 and forskolin raised intracellular cAMP level of Dermatophagoides farinae extract-reactive human T cell line and inhibited T cell receptor-stimulated IL-5 production. The cAMP analog, dibutyryl-cAMP, also inhibited IL-5 production, whereas the protein kinase A inhibitor, H-89, enhanced IL-5 production. The IL-5 production was completely suppressed by anti-IL-2 neutralizing antibody. Recombinant human IL-2 itself induced IL-5 production, suggesting that IL-5 production stimulated through T cell receptor is dependent on the autocrine production of IL-2. Prostaglandin E2, forskolin and dibutyryl-cAMP enhanced but H-89 suppressed recombinant human IL-2-induced IL-5 production. Prostaglandin E2 suppressed T cell receptor-stimulated mRNA expression of IL-2 as well as IL-5 in the T cell line, whereas it potentiated IL-5 mRNA expression stimulated by recombinant human IL-2. These results suggest that the inhibitory effect of cAMP on IL-5 production is mediated by the suppression of IL-2 production. On the contrary, IL-2-induced IL-5 synthesis is enhanced by increasing cAMP. Our study clearly indicated that cAMP regulates IL-5 production of human T cells by two differential effects.

Allergens↗
PubMed1996

IL-15 promotes cytokine production of human T helper cells.

IL-15 is a newly identified cytokine that has T cell and B cell growth factor activity similar to that of IL-2. In this study, a novel biologic function of IL-15 to promote cytokine production by human Th cells has been elucidated. Dermatophagoides farinae 11 (a major allergen of house dust mite)-specific human T cell clones produced IL-5 in response to recombinant human IL-15 as well as to either anti-CD3 or IL-2 stimulation. IL-5 mRNA became detectable 3 h after IL-15 stimulation and reached a maximum at 9 h. Human IL-5 promoter/enhancer-luciferase gene construct transfected to T cell clones was clearly transcribed in response to IL-15, indicating that the approximately 500-bp human IL-5 promoter/enhancer segment 5' upstream of the coding region sufficiently responded to IL-15. IL-15-induced IL-5 synthesis was completely inhibited by the tyrosine kinase inhibitor, herbimycin A, suggesting the involvement of tyrosine kinases in the signal transduction leading to IL-5 synthesis as well as to proliferation of T cells induced by IL-15. Whereas IL-5 production by human peripheral T cells was abolished by the addition of anti-IL-2-neutralizing Abs into the culture, IL-15 restored the IL-5 synthesis despite effective IL-2 neutralization. IL-15 produced at the site of allergic inflammation may play a role in the recruitment and activation of eosinophils by inducing IL-5 (a Th2 cytokine) production by T cells.

Actins↗
PubMed1996

A new assay system detecting antibody production and delayed-type hypersensitivity responses to trinitrophenyl hapten in an individual mouse.

A new assay system detecting antibody production and delayed-type hypersensitivity (DTH) responses to trinitrophenyl hapten in an individual mouse (AS-DAD) was established. BALB/c mice were immunized intraperitoneally with varying amounts of 2,4,6-trinitrophenylated sheep red blood cells (TNP-SRBC) on day 0. Venous blood was collected on days 2, 4, 6, 8 and 10. Levels of anti-TNP IgM and IgG serum were assayed by enzyme-linked immunosorbent assay (ELISA). After series of bleeding the mice were challenged with 2,4,6-trinitrobenzene sulfonic acid (TNBS) solution in the footpad on day 14. Footpad swelling was measured 24 or 48 h after the challenge. Peak responses of the anti-TNP IgM and IgG production were detected 4 or 6 days after the immunization with 10(9) TNP-SRBC. Maximum DTH response was also observed with 10(9) TNP-SRBC 24 h after the challenge on day 14. The antibody and DTH responses were also induced in other normal inbred strains such as C3H/He and DBA/1 but not BALB/c nu/nu mice. To evaluate AS-DAD in immunopharmacological studies, various immunomodulating agents were examined in BALB/c mice by subcutaneous administration on days 0, 1, 2 and 3. Cyclosporin or cyclophosphamide at 100 mg/kg/day completely inhibited not only the anti-TNP IgM and IgG production but also the TNP-specific DTH response. Prednisolone at 0.5 mg/kg/day had no significant effect on the IgM and IgG production, whereas it inhibited the TNP-specific DTH response. Interestingly, histamine-added mouse gamma-globulin at 150 MG/kg/day clearly enhanced the anti-TNP IgM and IgG production, while it showed a suppressive effect on the TNP-specific DTH response. Levamisole at 5.0 mg/KG/day showed suppressive effects on the anti-TNP IgG production without affecting the IgM production and the DTH response. These results suggest that AS-DAD is useful for evaluating the immunopharmacological action of various agents.

Animals↗
PubMed1996

A critical role of IL-2 for the production and gene transcription of IL-5 in allergen-specific human T cell clones.

The role of IL-2 in IL-5 synthesis of human helper T cells was investigated. All of the Der f II (a major allergen of house dust mite)-specific T cell clones established from atopic asthmatic patients produced both IL-2 and IL-4 upon activation (Th0 phenotypes). Recombinant IL-2 induced gene expression and protein synthesis of IL-5 in T cell clones that produced IL-5 upon antigenic stimulation. Human IL-5 promoter/enhancer-luciferase gene construct transfected to T cell clones was clearly transcribed in response to IL-2, indicating that the approximately 500 bp gene segment 5' upstream of the coding region was functionally sufficient for the gene transcription induced by IL-2. IL-2-induced IL-5 synthesis as well as proliferation was dependent on tyrosine kinases. Moreover, IL-5 production by T cell clones stimulated with immobilized anti-CD3 antibody was completely abrogated by anti-IL-2 neutralizing antibody, suggesting that IL-5 (a Th2 cytokine) synthesis of human helper T cells is dependent on IL-2 (a Th1 cytokine). Our present findings clearly demonstrated that IL-2, known as a T cell growth factor, exerts a cytokine promoting activity on T cells. IL-2 produced at the site of allergic inflammation might facilitate eosinophilic inflammation by inducing IL-5 production in T cells.

Allergens↗
PubMed1996

Direct expression of Der f2, a major house dust mite allergen, in Escherichia coli.

Der f2 protein in a highly antigenic form was directly expressed in bacteria. Plasmid pFLU11 derived from pKK233-2 was designed to express methionyl-Der f2 under the control of the trc promoter and it has the replication origin of pUC118 instead of its original to increase the copy number. This expression plasmid directed the synthesis of recombinant Der f2 (rDer f2) protein in an insoluble form of inclusion bodies in Escherichia coli cells. The high copy number plasmid pFLU11 conferred the efficient production of the Der f2 protein in E. coli, when compared to a nonchanged origin material. rDer f2 inclusion bodies were easily solubilized in urea and renatured by dialysis to assume the active form. The rDer f2 protein was purified by means of anion exchange and gel filtration chromatography. This expression system yielded about 10 mg of purified rDer f2 protein from the 1L culture. Purified rDer f2 protein reacted with IgE from patient sera almost identically to the native Der f2 in the RAST enzyme immunoassay and skin prick test.

Allergens↗
PubMed1996

A novel phosphodiesterase inhibitor, T-440: possible management of eosinophilic inflammation by down-regulation of interleukin-5 production.

The effect of T-440, a selective type IV phosphodiesterase (PDE IV) inhibitor on interleukin (IL)-5 production by peripheral blood mononuclear cells (PBMCs) of atopic asthmatic subjects was investigated. PBMCs produced IL 5 following challenge with specific allergen in vitro. T-440 suppressed allergen-induced IL-5 production significantly at a concentration of 1 microgram/ml. T-440 inhibited cyclic AMP-phosphodiesterase (PDE) activity in a concentration dependent manner and raised the intracellular cyclic AMP level of PBMCs significantly. Dibutyryl cyclic AMP suppressed IL-5 production by PBMCs in a similar way to T-440, suggesting that the increase of intracellular cyclic AMP caused by T-440 reduces IL-5 production. T-440 may be an effective agent to treat atopic diseases associated with eosinophilic inflammation, e.g. asthma and atopic dermatitis.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1996

[Molecular biological analysis of house dust mite allergens].

Using a host-vector system of Escherichia coli, we could produce one of major house dust mite allergens, Der f II in large quantity for therapeutic and diagnostic purposes. About 5 mg of purified and biologically active rDer f II was obtained from one liter culture, which was corresponding to the amount in about 30 g of live mite. The rDer f II was almost identical with native Der f II with respects to biological and physicochemical view points. Native mite Der f II is a mixture of several kinds of Der f II molecule with a few amino acid substitutions, which were due to polymorphisms among individual mite gene sequence. We had cloned three kinds of Der f II cDNAs from mite culture and expressed in E. coli and prepared three kinds of rDer f II in this system. As a result of comparison of IgE binding activity among three rDer f IIs and nDer f II, there was no significant difference observed.

Allergens↗
PubMed1996

[Blood pressure and renin in long-term hemodialysis patients].

Blood pressure (BP), plasma active renin concentration (ARC), plasma renin activity (PRA), aldosterone (Aldo), atrial natriuretic peptide (HANP), plasma sodium (Na), plasma potassium (K), total protein (TP), hematocrit (Ht) and body weight (BW) have been measured in 101 patients, including 9 diabetic patients, undergoing hemodialysis for 5 through 278 months. BP, ARC, PRA and HANP correlated inversely with the duration of dialysis. Among 13 patients undergoing hemodialysis for more than 20 years, only one patient received antihypertensive drugs. This finding suggested that relative low ability of renin secretion and a slightly low concentration of HANP causes low blood pressure in long-term dialysis patients. ARC was significantly correlated with PRA, Aldo, Na, TP-A (TP concentration after hemodialysis), Ht(delta)% (difference between before and after hemodialysis) and BW(delta)%. These investigations suggest that the removal of large quantities of water and salt in each dialysis session may cause excessive secretion of renin. Though no relation was demonstrated between ARC and blood pressure in 101 patients, ARC was correlated significantly with blood pressure in 37 non-DM patients undergoing hemodialysis for less than 10 years and was inversely correlated in 55 non-DM patients undergoing hemodialysis for more than 10 years. Therefore, further analysis of other factors that maintain blood pressure, especially in long-term dialysis patients is required. Multiple regression analysis showed that major factors regulating the levels of blood pressure were duration of dialysis, Ht(delta)% and BW(delta)%. During dialysis, we observed significant correlation between ARC(delta)% and Ht(delta)%, but we did not find any correlation between the change in blood pressure and ARC. Furthermore, [correction of Forthermore] we found that caution should be paid to body water control especially in diabetic patients, because of their remarkable fall of BP during dialysis.

Adult↗
PubMed1996

Interleukin-5 production by peripheral blood mononuclear cells of asthmatic patients is suppressed by T-440: relation to phosphodiesterase inhibition.

The effect of T-440, a selective type IV phosphodiesterase inhibitor, on cytokine production by peripheral blood mononuclear cells (PBMC) of atopic asthmatics was investigated. T-440 suppressed allergen-induced interleukin (IL)-5 production with a high potency (IC50 = 0.039 microgram/ml) and allergen-induced proliferation of PBMC (IC50 = 0.30 microgram/ml). T-440 also suppressed IL-2, IL-4 and IL-5 production by concanavalin A-activated PBMC in concentration-dependent manner. The IC50 values for the suppression of cytokine synthesis were 0.11 microgram/ml for IL-2, 0.57 microgram/ml for IL-5 and 7.7 micrograms/ml for IL-4. cAMP-elevating agents, such as PGE2, forskolin and dibutyryl cAMP, suppressed IL-2, IL-4 and IL-5 production by concanavalin A-stimulated PBMC in a manner similar to that of T-440. T-440 inhibited cAMP-phosphodiesterase activity and raised the intracellular cAMP level of PBMC in a concentration-dependent manner, suggesting that the increase of intracellular cAMP caused by T-440 results in the reduction of cytokine production. We conclude that T-440 suppressed cytokine production by peripheral T lymphocytes via the protein kinase A pathway and may be an effective modality to treat atopic diseases associated with eosinophilic inflammation.

Adult↗